iPhone中解析JSON响应时出现问题

Question

我正在从此链接获取json数据

现在我要从“ html_instructions”中获取数据：part

NSDictionary *result = [stringtext JSONValue];
NSLog(@"here");
NSArray *resultarr = [result objectForKey:@"routes"];
NSString *string;

for(NSDictionary *di in resultarr){
    NSLog(@"for loop");
    string = [[di objectForKey:@"legs"] objectForKey:@"steps"];
}

但是在控制台中打印“ for loop”后，它将引发异常

2011-05-20 16:16:26.997 speedymap[759:207] -[__NSArrayM objectForKey:]: unrecognized selector sent to instance 0x62a7d60

2011-05-20 16:16:26.999 speedymap[759:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSArrayM objectForKey:]: unrecognized selector sent to instance 0x62a7d60'

请帮我，我想要html_instructiuons字段值

Answer 1

检查resultarr和di真的包含任何东西。

NSDictionary *result = [stringtext JSONValue];
NSLog(@"here");
NSArray *resultarr = [result objectForKey:@"routes"];
CFShow(resultarr);
NSString *string;

for(NSDictionary *di in resultarr){
    CFShow(di);
    NSLog(@"for loop");
    NSArray *tempArr = [[di objectForKey:@"legs"] objectForKey:@"steps"];
}

Answer 2

http://jsonviewer.stack.hu/#http://maps.googleapis.com/maps/api/directions/json?origin=delhi&destination=noida&waypoints=&sensor=true

检查查看器并相应地设置值。 [di objectForKey：@“ legs”]返回一个数组。 该数组的第一个对象是具有关键步骤的字典。 但这也返回另一个数组。